Haas VF4 Question

[Jim at Gentex]

We have a new Haas VF4 and are currently troubleshooting the post and running test programs.

 

When running a radial multiaxis surface program, we are seeing some stuttering movements as the tool nears the rotary axis zero, then it gets smooth again as it moves away from the rotation point.

 

Is this a Mastercam, post, or machine control setting issue?

 

Thanks.

[Josh T™]

Hey Jim,

 

Are you using Inverse Feed Rates? If not give it a try and see if helps... same issue here a while back.

 

HTH

Josh

[Jayson Kramer]

if it is an old control and does not have look ahead it will do that as the moves get smaller and more data to read.

[Namliek_J@TheeCircle™]

Make sure you turn the axis brake off for the axis which are rotating. I believe the codes are M11 and M13 if running a trunion. Usually we insert a manual toolpath and put those codes in before the multiaxis toolpath to ensure that the axis brakes are not engaged. HTH.

[Jim at Gentex]

Thanks guys.

 

We just heard back from our reseller and they also suggested trying inverse feed rates. That's probably going to do it.

 

It's a brand new machine, and yes, the axis brakes are turned off.

 

I was just wondering if there was something else obvious that we're missing in the control settings.

 

Thanks again for the help.

[chris m]

My buddy's VF2 had some issues with choppy movements when we were playing around with some surfacing work because he didn't have the HSM option from Haas and the machine just wouldn't process the blocks fast enough. We kicked in the 'demo' of the HSM package from Haas and the problems went away.

[MotorCityMinion]

I also get the jerky movement with short, fast moves on a VF4, and that's in a vise, not the rotary. No HSM option here. The post is MPMASTER. As long as the tool stays down and there's some distance between the moves, things are fairly smooth.

[YoDoug®]

Getting the HSM option really helped our Haas mills in higher speed 3d cuts, but it is still a Haas and cannot process code as fast as our Fanuc machines. The same programs in our Haas mill that are jerky at high speed run much more smoothly in our Kia/Fanuc mills.

[Ed@Gentex]

Hi all, thanks for the replies. We have the VF-4SS with the TR160.

It has the HSM turned on, Machine control setting 85 is at .050, and I think it is setting 191 to smooth.

I changed the control def. to 3 axis to unit and the rest to inverse. Now the max feed rate is F1000. inverse and it seems really slow. I have a email into in-house telling them of the max feed rates of A,B are 80. DPS. X,Y,Z are 833 IPM and the rapids 1400 IPM on the XYZ, I think we are close to getting it ironed out.

 

Here are a few of the specs.

 

30 hp 12000 rpm direct drive spindle.

 

1.2 second tool changer.

 

HSM

 

programmable coolant nozzle.

 

Auto air blast.

 

300 psi thru the spindle coolant, cutting mostly composites so no need for the 1000 psi.

 

Glass scales on XYZ.

 

TR160 4th and 5th axis

 

1400 IPM rapids, 833 ipm cutting.

 

Auto doors.

 

coolant filter.

 

chip auger.

 

high intensity lighting.

 

16 MB of memory.

 

USB port.

 

 

Ed

[Ed@Gentex]

From cnc magazine.

quote:

---

cnc magazine

Dear Applications,

I have a ’97 model VF-3 vertical machining center with the fourth-axis option and an HRT 310 rotary table. Up until now I have only used the rotary table for indexing operations on simple parts. I recently bid on a job that will require full four-axis motion. My CAD/CAM system will support both feed-per-minute and inverse-time-feed modes but I am not familiar with inverse-time feed. Should I use inverse-time feed on full fourth-axis parts? What exactly is inverse-time-feed mode?

 

 

Sincerely,

Mark Curry

 

 

Dear Mark,

Inverse-time feed is not as complicated as it sounds. Inverse-time-feed rates simply dictate the amount of time a particular stroke will take to complete. To calculate the time for a stroke, divide the inverse-time-feed rate into 60. For example, an inverse-time-feed rate of F1000 dictates that the commanded motion of that line will take 0.06 seconds. This method of feed-rate command allows for more precise control of the feed rate when combining rotary and linear axes. With the Haas control you have the option of running in either inverse-time-feed mode or feed-per-minute. The Haas control can convert linear-feed-per-minute rates to approximated angular-feed-rates based on the user-definable part diameter stored in the 4th- and/or 5th-axis diameter setting(s). This feature allows the user to program a combination of linear and rotary axis motions in feed-per-minute mode, but the rotary feed rate will only be exactly correct at the diameter set by the user. Therefore, inverse-time feed is preferred when mixing linear and rotary axes because it is not a linear-feed-rate command, but rather a time-based feed command.

 

 

Sincerely,

Haas Applications

---

I will change this setting in the control on Monday. I know it is set to the default of 1.0000, the part is no less than 9. Let’s see if this fixes the max inverse feed of F1000. from running slow.

 

Ed

[YoDoug®]

lowering the .05 value in setting 85 may help. This is the tolerance that the control uses to decide how much to slow feedrates down in corners. When I am doing reel high feed rates 200-300 IPM I will change setting 85 to .001, This smooths out the jerky movements.

[Ed@Gentex]

Doug,

 

The manual that came with the HAAS says for live 5 axis machining to have setting 85 no less than .050 the default was .025. If I still have the jerky movement after setting the dia for the 4th and 5th axis to 9.000, I will try turning setting 85 down to a lower value.

 

I will keep you posted.

 

Ed

[Rocketmachinist]

From cnc magazine.

</font>

<font size="1" face="Verdana, Helvetica, sans-serif, Arial">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif, Arial">

cnc magazine

Dear Applications,

I have a ’97 model VF-3 vertical machining center with the fourth-axis option and an HRT 310 rotary table. Up until now I have only used the rotary table for indexing operations on simple parts. I recently bid on a job that will require full four-axis motion. My CAD/CAM system will support both feed-per-minute and inverse-time-feed modes but I am not familiar with inverse-time feed. Should I use inverse-time feed on full fourth-axis parts? What exactly is inverse-time-feed mode?

 

 

Sincerely,

Mark Curry

 

 

Dear Mark,

Inverse-time feed is not as complicated as it sounds. Inverse-time-feed rates simply dictate the amount of time a particular stroke will take to complete. To calculate the time for a stroke, divide the inverse-time-feed rate into 60. For example, an inverse-time-feed rate of F1000 dictates that the commanded motion of that line will take 0.06 seconds. This method of feed-rate command allows for more precise control of the feed rate when combining rotary and linear axes. With the Haas control you have the option of running in either inverse-time-feed mode or feed-per-minute. The Haas control can convert linear-feed-per-minute rates to approximated angular-feed-rates based on the user-definable part diameter stored in the 4th- and/or 5th-axis diameter setting(s). This feature allows the user to program a combination of linear and rotary axis motions in feed-per-minute mode, but the rotary feed rate will only be exactly correct at the diameter set by the user. Therefore, inverse-time feed is preferred when mixing linear and rotary axes because it is not a linear-feed-rate command, but rather a time-based feed command.

 

 

Sincerely,

Haas Applications </font><hr />

<font size="2" face="Verdana, Helvetica, sans-serif, Arial">I will change this setting in the control on Monday. I know it is set to the default of 1.0000, the part is no less than 9. Let’s see if this fixes the max inverse feed of F1000. from running slow.

 

Ed

 

So did it start to move faster. I am playing around with my 5 axis right now and have the same problem. It is feeding at 999.99 feedrate but the table looks like it's moving at 5% rapids. If anyone has any idea about how to fix this that would be awesome.

[mkd]

shouldn't setting 85 "contour accuracy" be more jerky at a lower decimal value??

setting this value to a higher number will decrease the jerkiness and cycle time, from my experience.

you can also play with programming G187 E.xxx in the same manner. big number for smooth, small number for accuracy.

[crazy^millman]

It is feeding at 999.99 feedrate but the table looks like it's moving at 5% rapids

 

See if the machine will take 9999.99 feedrate. If it will change the machine def or control def or the post to allow it to and see if that help. I have seen that problem on many 5 axis machine were the code was not big enough for the correct inverse time.

[Bob W.]

I believe the Haas will do 40,000 moves per minute with the inverse feed rate activated. With small surfacing moves it is critical to set this as high as the machine will take. It is a machine definition, control definition, or post setting. Also, things run much more smoothly if the rapids are output as max feed rate moves. Before I went to that approach it would vibrate like crazy during rapids because the X, Y, and Z axes get to the final position much faster than the rotary axes. The last thing to do is just slow down the program. The Haas will not run 5-axis surfacing toolpaths very fast because the trunnion is slow and under-powered. I have a VM3 with a TR-160.

[Rocketmachinist]

I think your right. I found this video online and look at the feed rate. It looks like 2535. I think I just need to crank that sucker up.

 

[Bob W.]

I think your right. I found this video online and look at the feed rate. It looks like 2535. I think I just need to crank that sucker up.

 

 

Yup, that is mine :-)

[Rocketmachinist]

Really then I just sent you a message on youtube then about this particular thing.

[Bob W.]

I called Haas some time ago and if I recall they said the max inverse time the machine can handle is 40000. The speed in the video is as fast as I can get that trunnion to go, period. If your machine definition is limiting your inverse feed rate to 999 then you are being limited by that, and not the machine.

[mkd]

that must be the fastest i've seen a Haas trunnion run! nice program!

i worked on a trt210 in the past. something must have been wrong with the machine settings because it was more jerky running much slower.